Automatic delay starting and lock-out switch mechanism



March 23, 1954 R. L. ADAMS ET AL AUTOMATIC DELAY STARTING AND LOCK-OUTSWITCH MECHANIsM Filed March 16, 1950 2 Sheets-Sheet l TURBINE PUMPINVENTOB. EZIL'JEJfeaI/z;

ATTORNEY Mam}! 1954 R. L. ADAMS ET AL AUTOMATIC DELAY STARTING ANDLOCK-OUT SWITCH MECHANISM Filed March 16, 1950 2 Sheets-Sheet 2INVENTOR.

Patented Mar. 23, 1954 AUTOMATIC DELAY STARTING A'N'D JOCK-GUT SWITCHMECHANISM Lee Adams and iI-Iollis .Herbert .Rieavis,

Ghildress, Tex.

ApplicationMarch 16, 195'0, SerialNo. '150;09'2

6 Claims. 1

This invention relates to an automatic delay starrtlngand lodk outswitch mechanism *for :controlling the operation of magnetic startersfor electric motors; and particularly, the motors employedfor drivingthe pumps in irrigation systerns.

In many large areas, the water for irrigation is stmplied from aplurality of wells "which vary in depth, the water being delivered bymotor driven pumps to irrigation ditches or canals from which itis'drawn on :and supplied to the fields by a seriies rof siphon tubes. -Asufficient number of such tubes is provided to siphon out the maximumamount of water -supplied to the ditches or canals Hey the pumps.

The power for the pump =motors is supplied over many miles -of lines;and due to weather conditions, .and/ or other factors, the power to thepumps is "frequently interrupted, causing -the iarmers, ranchers, andothers, serious inconveniences and expense. hfter anIinter-ruption 'ofthe power supply, the motors must be started as soon as possible afterresumption of the supply to avoid having -'-the water in the ditchesdrop below the siphon tubes wliich'wouldrequire each oi'the many tubesto be reprimed.

The motors for driving the individual pumps are provided with amagnetically actuated starter, usually controlled by 'a manuallyactuatedswritch:ofanysuitaible type; and the starters could be so wiredthat the several starters would rail rhexactuated :as :soon :as power onthe line is resumed. However, this is impracticable as it wouiddrequentlyrresult in serious damage to some oi the motors and pumps.been interrupted, the: pumps and motors start in reverse due to thewater :in the pum-p flowinghaok intowthe Wells. Itis obvious that thisdraining of thepumps (takes a longer timaein the deepwells thaniin themore shallow *ones. This time factorin the several 'wellsmay wary fromabout thirty seconds to several minutes; and should the power be resumedbefore :the pumps Of'Lth'B deeper wells have been fully drained and thereverse movement-of :thegpnmps and motors stopped, such pumps :andmotors would be seriously damaged. For this reason .it has heretoforebeen necessary to have an attendant at each pumping :station, whichstations are 'frequen-tlymiles apart, to set intooperation the pumpunder :his care as soon .as, but not before, (the pump is fully drained..I-his is done by closing a switch in the circuit to the actuating coilof theimag-netic starter. As

:such starters ame sold well known inv the not,

As soon aspowerhas The objector the present invention is to provide anautomatic :delay starting :mechanismrat each :pumping station whichshall close the circui't to the magnetic starter when, and onlywhen, therespective pump has been fully drained and the reverse movement of thepump and motorchas stopped.

A 'iurther object of the invention .is toipr'ovide a device of the classmentioned which shall .be

1 of comparatively simple construction, and which may be readilyinstalled at relatively small "cost.

A further object of the invention :is to provide adevice as'mention-edwhichimay beireadilytimed to coordinate the same to the "time required'to drain the pump with which .it is installed.

A further object of the invention is to provide an automatic delaystarting switch which will operate successfully irrespective of thenumber and frequency of the current interruptions.

(Ether objects will appear hereinafter.

With these objects in view, the invention comprises =a tiltable timingarm upon which is mounted a pair of mercury switches, which areconnected in series with each *other and .in series with the magneticstarter of "a pump actuating motor with which the device is to he used.The mercury switches are 'iangularly arranged with relation to eachother 'so that when the timing arm is slowly tilted by suitable meansreleasable upon failure of :power of themotor, both switches are closedif or a predetermined time during the movement of -the timing arm; butat for near the limit of movement in either direction, one 'of saidswitches is open. Should the power be resumed during the period whenboth of said switches are closed, the circuit to 'thexmotor starter willhe completed, and the pump started into operation. Should the resumption'Df power he delayed until "the :arm has moved sufficiently to breakthe:circuit in one of the switches, the motor will be locked out ofoperation'until' the circuit to the motor starter has been manuallyclosed, :as will be fully described hereinafter.

'Ihe invention further consists in means whereby the angular positionsof the mercury switches may .be readily adjusted in order to synchronizetheiperiod within which both switches remain closed to the time requiredto drain the pump of the well with which. the device is to be used.

"-lfhe invention further consists in means whereby the timer will beautomatically reset 'as soon as power in the motor circuit is resumed.

The invention further consists in various details of construction :andarrangement of "parts, as will be described hereinafter and particularlypointed out in the claims.

The invention will be more readily understood by reference to theaccompanying drawings, forming a part of this specification and inwhich:

Fig. 1 is a front elevation of a switch mechanism embodying theinvention, illustrating the several elements in their normal positionswhen the power current is on and the motor and pump in operation;together with a diagram of the circuits to the motor and the usualmagnetic starter;

Fig. 2 is a similar elevation of the device, with the elements at theextreme opposite positions they may assume when the current is off;

Fig. 3 is an end view of the same, with the reset spring broken away;

Fig. 4 is a detail view illustrating the switch elements in anintermediate position, and

Fig. 5 is a detail sectional view illustrating the timing adjustment ofthe switches.

The mechanism comprising the invention may be mounted in any suitablemanner, such as a vertical supporting panel I9 having a horizontal baseII. This may be made of sheet metal of suitable gauge; and the entiremechanism may be enclosed in a box or case which is not illustrated, asit forms no part of the present invention.

Secured to the panel H3 is a timing device which comprises a springactuated clocking mechanism [2, and a timer shaft l3 upon which is fixeda preferably T-shaped member comprising a timing arm [4 and a dependingreset arm [5.

Mounted upon the arm I4 is a pair of mercury switches 16 and Il, whichwill be hereinafter referred to as the starting switch and the lockoutswitch, respectively. The switches l6 and ll are each provided adjacentone end with the usual contacts I9 and I1; and said switches arepreferably arranged with these contact ends remote from each other.

The switches I6 and I! are each supported in a clamp bracket I9pivotally connected as by bolts l9, to the arm l4 adjacent the endsthereof, so that the angular positions of the switche may be adjusted totime the operation of the device, as will be more fully describedhereinafter. Pivotally connected to the arm 14 as by bolts 20, are bracearm 2| having slots 22 to receive bolts 23 which extend through thelower ends of the clamp brackets l8. It is obvious that by thisarrangement the switches may be readily adjusted to the desired angleand securely clamped in position by tightening the several bolts.

Supported upon the'panel Ill above the timing mechanism 12 is a bar 25,preferably of insulating material, and provided with terminals 26, 21,and 28. One contact of the timing switch 16 is connected by a flexibleconductor 29 to the terminal 26, and the other contact thereof to theterminal 21 by a conductor 30. The contacts of the switch I! areconnected to the terminals 21 and 28 by flexible conductors 3| and 32respectively.

The terminal 26 is connected by a line 34 to one terminal 35 of themagnetic starter 38, and the terminal 28 is connected to anotherterminal 31 of the starter by a line 38. A normally open, manuallycontrolled switch 39 is shunted across the lines 35 and 38 for a purposehereinafter described. A starter maintaining line 40 is pro vided with anormally closed switch 4| whereby the motor may be readily stopped whennecessary while the power is on.

In the diagram included in Fig. 1, 45 indicates a turbine pump, and 46 athree phase motor for operating the same.

The normal position of the timing arm [4 is as illustrated in Fig. 1,and the arm is held in this position by a reset mechanism. The resetmechanism comprises generally a reset lever 41 having a detent 48 forengaging the reset arm l5 of the timer, a solenoid 49 for normallyholding the arm IS in set position when the motor 49 is running, and aspring 50 for retracting the lever 41 when power to the motor isinterrupted, thereby releasing the timing mechanism. The solenoid 49 isshunted across the motor circuit between the starter and the motor, asindicated in Fig. 1. Conductors 5| and 52 connect the solenoid toterminals 53 and 54 on the bar 25, and said terminals are connectedacross the motor circuit by lines 55 and 56. An arm 51 extends outwardlyfrom the panel l0 constituting a safety stop for the reset arm l5; andthe conductors 5i and 52 leading from the solenoid 49 to the terminals53 and 54 extend through a supporting loop 58 on said arm.

The reset lever 41 is pivotally mounted on the base, as at 60, and isconnected to the movable core SI of the solenoid 49 by a link 62.

The operation of the device is as follows: When the power to the motoris on, the magnetic starter is maintained in closed position by theusual magnetic coil, the circuit of which includes the maintaining line49. As such starters are of various well known designs, and as thedetails of the starter constitute no part of the present invention,detail description and illustration thereof is believed to besuperfluous. Also, when the motor is in operation the solenoid 49 isenergized, thereby maintaining the reset lever 41 in position to holdthe timing mechanism in inoperative position, as illustrated in Fig. 1.As soon as the current to the motor is interrupted to solenoid 49 isde-energized and the spring 50 retracts the reset lever into theposition illustrated in Fig. 2. This permits the timing mechanism tostart moving the T-shaped member l4-l 5 slowly in a counterclockwisedirection.

It will be noted that initially the contacts I1 in the lock-out switchI! are closed by the mercury therein, whereas the contacts IS in thestarter switch It are open. As the movement of the arm l4 continues thetimer switch is tilted until the mercury therein engages the contactsl6, closing the switch and connecting the two switches l8 and I! inseries with each other, and in series with the magnetic starter.

Fig. 4 illustrates a position where both switches are closed.

Should the power be resumed while both switches l6 and I1 are closed,the magnetic starter will be energized, closing the circuit to the motorand starting the pump into operation.

As soon as the motor is started the solenoid 49 will be energizedthereby quickly throwing the lever 41 into initial position; and thedetent 48 thereon will engage the arm l5 and restore the timingmechanism to normal position and at the same time rewind the clock-worktiming mechanism.

Should the current remain "off until the lockout switch I! has movedinto position to open the same, the mechanism will be locked so that themotor cannot start upon resumption of power until the switch 39 ismanually closed. This is necessary, as when the pumps are inactive for alonger period than timed by the switches, it is likely that the siphontubes will need repriming before the pumps are started; and should thepumps start working automatically without the owner or attendant havingknowledge of the conditions, considerable damage would usually beincurred.

It is necessary when power to a turbine pump motor fails, that the powershall not be restored to the motor until the water has completelydrained from the pump, and all reverse movement of the pump and motorhas ceased, as hereinbefore explained. Also it is necessary to start themotor as soon as possible after the power has been resumed. Thereforeeach of the starting mechanisms must be timed according to the depth ofthe well with which it is used. It is for this purpose that the mercuryswitches are mounted for angular adjustment on the timer arm M. By thisarrangement the length of time that the contacts of both tubes remainsimultaneously closed may be nicely regulated. After the solenoid hasbeen de-energized, it takes approximately ten minutes for the reset arml5 to be L moved by the spring mechanism from the position shown in Fig.1 to that shown in Fig. 2; and as the time necessary to drain the pumpsvaries from about thirty seconds to approximately four minutes, avproper adjustment of the device for use with a specific well may readilybe made.

The manner of adjusting a switch is illustrated in Fig. 5.

When the device is once timed, no further adjustment is necessary. Thetime desired for closing the starting switch 16 will average about oneand a half minutes; and the average time for opening the look-out switchI! will vary from about six to nine minutes. In cases where a lock-outis not necessary, a connection or jumper may be provided to connect theterminals 2'! and 28. Such connection is indicated by dotted line 63 inFig. 1.

While a specific form of the invention has been illustrated anddescribed, it is to be understood that various changes may be madetherein without departing from the invention as defined in theaccompanying claims.

We claim:

1. In an irrigation system, a turbine pump, a motor for actuating saidpump, and a magnetic starter for said motor, in combination with controlmechanism for said starter comprising a tiltable member, clockworktiming mechanism for actuating said tiltable member, a pair of mercuryswitches mounted on said tiltable member and connected in series witheach other, and in series with said starter, a solenoid shunted acrossthe motor circuit normally holding said tiltable member in position tomaintain one of said switches in closed position, and the other switchin open position, spring means operable upon failure of current in saidstarter and said solenoid for releasing said tiltable member to permitsaid timing mechanism to gradually move said tiltable member to closethe normally open switch and after a predetermined time to open thenormally closed switch.

2. The combination as set forth in claim 1, further characterized bymeans for adjustably mounting said switches on said tiltable member.

3. The combination as set forth in claim 1, further characterized by amanually operable, and normally open, switch shunted across the circuitbetween said mercury switches and said starter.

4. In an irrigation system, a turbine pump, an electric motor for saidpump and a magnetic starter for said motor, a timing shaft, escapementcontrolled spring actuated means for gradually rotating said shaft whenreleased, a tiltable timing arm fixed to said shaft, a normally openstarting switch and a normally closed lock-out switch, both of themercury type and each adjustably mounted on said timing arm, saidswitches being connected in series with each other, conductorsconnecting said switches in series with said starter, a normally openmanually operable switch shunted across said conductors, a reset armextending rigidly from said timing arm, a pivotally mounted reset lever,a solenoid shunted across said motor circuit between said starter andsaid motor and adapted when energized to retract said reset lever, adetent on said reset lever adapted to engage said reset arm and holdsaid timing arm in normal position when said solenoid is energized, anda spring for retracting said reset lever and releasing said reset armwhen said solenoid is de-energized.

5. In an irrigation system, a turbine pump, a motor for said pump. and amagnetic starter for said motor, in combination with control mechanismfor said starter comprising a tiltable member, a pair of mercuryswitches mounted in said tiltable member and connected in series witheach other and in series with said starter, one of said mercury switchescomprising a lock-out switch and the other a starting switch, a solenoidshunted across the circuit to said motor for normally holding saidtiltable member in position to maintain said locking switch closed, andthe starting switch open, means operable upon failure of current in saidmotor and said solenoid for releasing said tiltable member, and meansfor gradually tilting said tiltable member to close said starting switchand to open said lock-out switch at a predetermined time thereafter.

6. The combination as set forth in claim 5, further characterized by amanually operable, normally open starting switch shunted across thecircuit between said mercury switches and said magnetic starter.

ROBERT LEE ADAMS. HOLLIS HERBERT REAVIS.

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